Propeller construction



Jan-'19, 1932. H. T KINGSBURY PROQFELLER CONSTRUCTION Filed Jan. 51, 1930 Patented Jan. 19, 1932 m'rao STATES HARRY '1. KINGSIBURY, OF KEENE NEW HAMIPSHIRE' PROPELLER CONSTRUCTION Original application filed June 19, 1929, Serial No. 372,128.: lllividlad. and:

31, 1930. Serial, 1110; 424,982.

This invention relates to improvements in the construction of propellers, and is a division of my copending application Ser. No. 372,128 filed June 19, 1929.

It has already been proposed to construct propellers of sheet metal, and the present invention concerns a method of forming and assembling such propellers, and is particularly adapted for propellers to be employed on toy airplanes.

One of the objects of the present invention is to provide a form of propeller which may be made from simple parts by punching and forming operations, and wherein the prpeller is stiffened and reinforced during the forming operation to resist the stresses upon it.

An illustrative form of propeller according to the present invention is set forth on the accompanying drawings, in which:

Figure 1 is a view of one of the blanks from which the propeller may be assembled.

Fig. 2 is a similar view, showing the finished propeller.

Fig. 3 is an axial section on line 33 of Fig. 2.

In the drawings, a sheet of metal is stamped or otherwise cut to provide a blank 10 having generally the form ofthe blade of the propeller to be assembled, but of greater dimension than the finished size of this blade so that a peripheral portion 11 is provided, which is illustrated as being of substantially uniform width. At the hub end of the blank, this peripheral portion 11 is cut away to leave a projecting portion tab 12, with outwardly diverging edges and having a boss 13 thereon extending across the propeller axis in the direction of the length of the blade, and a pair of bosses 14 extending along the axis, to provide arches to receive the propeller shaft. The portion of the blank tapers slightly to reduce its width toward the axis line, while the portion 12 is of symmetrical form, and has its widest portion at the free edge 15.

The assembled propeller comprises two symmetrical blanks of the type shown by Fig. 1. These two blanks are placed one over the other, with the arches 14 of the respective this application filed.- January blanks opposite one another toaprovide a, tunnel or. hole for the-reception of the shaft S. The flanges 11 are then curled: over whereby to form the stiffening beads 11a at the edges of the operating portion of the finished propeller, and also to engage over the projecting tabs 12 of the other blank. Owing to the outward divergence or angularity of the edges 16, the beads 11a thus hold the two portions of the propeller fixedly together, so that the sections may not be separated from one another. It will be noted that the stiffening and clamping beads 11a terminate close to the arches 14, so that the latter prevent any radial movement of the two halves of the propeller towards or from one another.

In Fig. 3, the arches 14 are shown to provide the tunnel for the shaft S shown in dotted lines in this figure, while the bosses 13 project farther away, and stiffen the assembled propeller across the axis.

It is obvious that the invention is not limited to the form of construction shown, but that it may be modified in many ways within the scope of the appended claims.

I claim:

1; In a toy airplane propeller, two overlapping identical elements each providing a blade, each element being narrowest at the propeller axis and wider in each direction from the axis, and having edge portions folded over the edges of the overlapping portion of the other element whereby to prevent radial movements of the elements with respect to one another.

2. In a toy airplane propeller, two identical elements each providing a blade, each element having bent-over edges adjacent the hub and having a tab extending beyond the propeller axis and overlapping the said other element, each said tab being wider at points removed from the axis than at the axis and being located between the said other element and its bent-over edges.

3. In a toy airplane propeller, twooverlapping identical elements each providing a blade and having an outwardly divergent tab extending beyond the propeller axis, and overlapping the other element, a boss on each element extending outwardly and inthe direction of the length of the blade, each tab havin arched portions adapted to receive the propeller shaft between the tabs, and bentover edges on each element for embracing and holding the tab of the other element.

4. In a to airplane propeller, two elements each provi ing a blade and having a tab extending past the propeller axis in overlapping relationship, the edges of each element having rebent portions to embrace and hold the tab of the other element.

5. A toy airplane propeller as in claim 4 in which the propeller elements are provided with outwardly directed boxes extending across the propeller axis for stifi'ening the propeller at the axis line.

In testimonfi whereof, I aflix my si nature.

ARRY T. KINGSB RY. 

